Nations Need to Adapt to Climate Change, Experts Say at EurekAlert! Chat

Michael Oppenheimer

By 2100, the Earth could be the warmest it has been for millions of years, and two climate experts warn that humans will need to adapt to the change even as we look for ways to reduce the greenhouse gas emissions that fuel the warming.

"Yes, it looks like we are headed toward a climate change that is largely irreversible on human time scales, in other words on the order of centuries, and some of the changes may never be reversed," said Princeton University climatologist Michael Oppenheimer during an hour-long online chat hosted by EurekAlert!, a service of AAAS.

Daniel Schrag, a Harvard climate researcher who also participated in the chat, said humans should prepare for climate change's effects on agricultural growing seasons, the spread of disease and even changes in insurance for coastal communities and homes in areas prone to extreme weather.

Daniel Schrag

"The big challenge is what happens if sea level predictions are wrong, and sea level rise is worse than we think. Then evacuating huge areas—like all of south Florida—becomes essential, and how a society deals with that kind of relocation is pretty complicated," Schrag said after the chat.

"The problem with all of these types of dangers is that we don't know when this will occur or even whether we have crossed a critical threshold already," Schrag explained. "We may have already lost control of the system, but I hope not, because reducing our own carbon emissions is something that is very feasible."

Oppenheimer, director of the program in Science, Technology and Environmental Policy at Princeton's Woodrow Wilson School, is a lead author on the Intergovernmental Panel on Climate Change's most recent global climate reports. Schrag, a 2000 MacArthur Fellow, studies climate changes across a broad span of Earth history and helped develop the "Snowball Earth" theory of global glaciation and multicellular evolution.

EurekAlert! is the world's premier science news Web site, receiving an average of one million visits a month. The online chat was the third in a series funded by the New York Times Co. It was moderated by Jesse Smith, senior editor of Science. The chat received over 4,500 visitors, including science reporters representing such publications as Die Zeit in Germany, the Independent in the United Kingdom, the Australian, BBC News, and Biofuels News, among others.

Both Oppenheimer and Schrag were less sanguine about whether national governments, particularly in the United States, have the political will to move aggressively to control emissions soon.

"The U.S. is gradually developing greenhouse [gas] policy, but only at the state level. We cannot expect a national program to be implemented for a few years," said Oppenheimer.

Although critics in the United States and elsewhere argue that the cost of emission controls will cripple national economies, Schrag said the cost may be "less than 1 percent of world GDP, and yet this still seems too expensive to us to protect against [the] possibility of catastrophic change."

A 2001 report by the Intergovernmental Panel on Climate Change estimated that global average temperatures will rise between 2.5 and 10 degrees Fahrenheit between 1990 and 2100—a rate of warming that is unprecedented for the past 10,000 years, according to the IPCC consensus.

Oppenheimer said there is little doubt that human activity is responsible for the warming trend, and that objections raised by skeptics "have been knocked down by research scientists one after the other, like a bunch of bowling pins."

Some science reporters who attended the chat questioned the researchers about the European Union's goal of limiting warming to 3.6 degrees Fahrenheit above the pre-industrial global temperature average. Oppenheimer said the goal is a good "precautionary target" but added that "it's a very tight target, and given what we know today about emissions of the greenhouse gases, I'd say we have at best a 50-50 chance of meeting it."

Individuals can help reduce emissions by making changes like switching to compact fluorescent light bulbs and driving fuel-efficient cars, said Oppenheimer. Schrag agreed, but cautioned that personal conservation was not enough to fix the emissions problem.

The researchers said increased use of biofuels, along with wind and solar power and carbon storage technology, would probably play a role in the strategy that humans would adopt eventually "to slow and eventually stop the warming. However, some further warming is inevitable, Oppenheimer said.

Oppenheimer said all countries need to devote resources to adaptation strategies, citing the United States' response to Hurricane Katrina as evidence that "our ability to deal with climate extremes, whether they have to do with global warming or not, is extremely limited."

For the complete transcript of the online chat, click here. Click here for a transcript of a past chat on nanotechnology and here for the evolution chat transcript.

Becky Ham

18 October 2006